Fix the problem that user supplied value not used in APER

For the following examplified ASN.1,

  TEST DEFINITIONS AUTOMATIC TAGS ::=
  BEGIN

  S1 ::= SEQUENCE  {
    fn INTEGER,
    fb BIT STRING DEFAULT 'A5'H,
    fc OCTET STRING DEFAULT 'FFAABB'H
  }

  END

and input XER as :

  <S1>
    <fn>9845</fn>
    <fc>DEAD9</fc>
  </S1>

The encoded APER should be :

  S1 ::= {
    fn: 9845
    fb: A5
    fc: DE AD 90
  }

but current output is

  S1 ::= {
    fn: 9845
    fb: A5
    fc: FF AA BB
  }

The reason is in SEQUENCE_encode_aper(), default_value_cmp() are
incorrectly checked against 1.

If the input value is equal to default value, this return value from
compare function is 0.

skeletons/constr_SEQUENCE.c

@@ -1835,7 +1835,7 @@ SEQUENCE_encode_aper(const asn_TYPE_descriptor_t *td,
 
 		/* Eliminate default values */
 		if(present && elm->default_value_cmp
-		        && elm->default_value_cmp(memb_ptr2) == 1)
+		        && elm->default_value_cmp(memb_ptr2) == 0)
 			present = 0;
 
 		ASN_DEBUG("Element %s %s %s->%s is %s",
@@ -1881,7 +1881,7 @@ SEQUENCE_encode_aper(const asn_TYPE_descriptor_t *td,
 		}
 
 		/* Eliminate default values */
-		if(elm->default_value_cmp && elm->default_value_cmp(memb_ptr2) == 1)
+		if(elm->default_value_cmp && elm->default_value_cmp(memb_ptr2) == 0)
 			continue;
 
 		ASN_DEBUG("Encoding %s->%s", td->name, elm->name);